Post by Deleted on May 3, 2013 16:36:49 GMT 10
I have just learnt a valuable lesson as a newbie in re-painting the exterior of my 22ft Viscount and I thought I would share it with you.
The previous owner had painted the exterior of the van with a gloss enamel house paint, and I didn't like his badly painted stripes or his paint job. The stripes didn't look anything like the Viscount flashes, and the rest of the van had some sloppy paint runs.
I decided to tidy up the exterior, remove the annex tracks, fill in the holes and repaint the exterior. After a day of sanding by hand I bit the bullet and purchased one of those nifty little Bosch hand sanders from Bunnings with a dust filter and it was worth every cent.
In some spots I had sanded back to the bare aluminium to get rid of paint runs, so decided to do it properly and prime the aluminium before the recoat. Was advised by Bunnings to use a Dulux RFU (Ready For Use) Etch Primer on the bare aluminium, as the other primers wouldn't stick.
After the paint had dried the etch primer went all wrinkly so instead of my aluminium being super smooth it looked like a dried up piece of passion fruit. I got a spray-painter mate to have a look at it and he says the term for this wrinkly paint effect is "pickling" which I had never heard of before.
Apparently pickling is caused by the reaction when an acrylic based paint is applied over an oil based paint, and in my case the edges of the oil based paint where it met the bare aluminium were the most reactive. However the reverse is not true, and an oil based paint can go over an acrylic without pickling.
The only way to get rid of it is to sand it back again - so I am so pleased I have my little hand sander!
Even though my pickling experience was a rection with a more recently applied house paint I imagine that most of the older caravans would have had an oil based paint for their sides.
I suppose the answer is if in doubt go for an oil based paint, unless you enjoy sanding back newly done work! Which is probably the reason why the previous owner used an oil based house paint...
The previous owner had painted the exterior of the van with a gloss enamel house paint, and I didn't like his badly painted stripes or his paint job. The stripes didn't look anything like the Viscount flashes, and the rest of the van had some sloppy paint runs.
I decided to tidy up the exterior, remove the annex tracks, fill in the holes and repaint the exterior. After a day of sanding by hand I bit the bullet and purchased one of those nifty little Bosch hand sanders from Bunnings with a dust filter and it was worth every cent.
In some spots I had sanded back to the bare aluminium to get rid of paint runs, so decided to do it properly and prime the aluminium before the recoat. Was advised by Bunnings to use a Dulux RFU (Ready For Use) Etch Primer on the bare aluminium, as the other primers wouldn't stick.
After the paint had dried the etch primer went all wrinkly so instead of my aluminium being super smooth it looked like a dried up piece of passion fruit. I got a spray-painter mate to have a look at it and he says the term for this wrinkly paint effect is "pickling" which I had never heard of before.
Apparently pickling is caused by the reaction when an acrylic based paint is applied over an oil based paint, and in my case the edges of the oil based paint where it met the bare aluminium were the most reactive. However the reverse is not true, and an oil based paint can go over an acrylic without pickling.
The only way to get rid of it is to sand it back again - so I am so pleased I have my little hand sander!
Even though my pickling experience was a rection with a more recently applied house paint I imagine that most of the older caravans would have had an oil based paint for their sides.
I suppose the answer is if in doubt go for an oil based paint, unless you enjoy sanding back newly done work! Which is probably the reason why the previous owner used an oil based house paint...
